KDE Software Compilation 4

KDE 4

Developer(s)	The KDE Team
Stable release	4.0 RC2 / 2007-12-11
Operating system	Unix-like
Type	Desktop environment
Website	http://www.kde.org/

KDE 4 is the forthcoming series of releases of the K Desktop Environment. The first version (4.0) of this series is scheduled for release on 11 January 2008.

The new series includes updates to several of KDE’s core components, notably a port to Qt 4. It will contain a new multimedia API, called Phonon, a device integration framework called Solid and a new style guide and default icon set called Oxygen. It will also include the new desktop and panel user interface tool, called Plasma, which will have support for desktop widgets, similar to SuperKaramba or Apple’s Dashboard widgets. The port to Qt 4 will facilitate support for non-X11-based platforms, including Microsoft Windows and Mac OS X. One of the overall goals of KDE 4 is to be more easily portable to different operating systems.

Major updates

This is a short overview of major changes in KDE 4. Not all of these changes will be available in the first (4.0) release

General

The port to the Qt 4 series is expected to make KDE 4 use less memory and be noticeably faster than KDE 3. The KDE libraries themselves have also been made more efficient. Qt 4 is available under the GPL for Mac OS X and Windows, which will allow KDE 4 to run on those platforms. The port of KDE 4 to Windows is still in an early state. During Google's Summer of Code 2007 an icon cache was created to speed up application start up times for use in KDE 4. Improvements were varied, as an application which used several hundred icons, Kfind, started up in almost a quarter of the time it took previously. Other applications and a full KDE session started up a little over a second faster.

Visual

The most noticeable change for users will be the new icons, theme and sounds provided by the Oxygen Project. These represent a break from previous KDE icons and graphics, which had a cartoonish look. Instead Oxygen icons will opt for a more photo realistic style. The Oxygen Project builds on the freedesktop.org Icon Naming Specification and Icon Theme Specification, allowing consistency across applications. The Oxygen team will be using community help for better visuals in KDE 4, with both alternate iconsets and the winners of a wallpaper contest held by the Oxygen project being included in KDE 4. There will also be a new set of human interface guidelines for a more standardized layout.

Plasma is a rewrite of several core KDE applications, like the desktop drawing and most notably the widget engine. Plasma will allow for a more customizable desktop and more versatile widgets.

KWin, the KDE Window Manager, will provide its own compositing effects, similar to Compiz.

Applications

Dolphin will replace Konqueror as the default file manager in KDE 4. This was done to address complaints of Konqueror being too complicated for a simple file manager. However Dolphin and Konqueror will share as much code as possible, and Dolphin can be embedded in Konqueror to allow Konqueror to still be used as a file manager.

Okular will replace several document viewers in KDE 3 like KPDF, KGhostView and KDVI. Okular makes use of software libraries and can be extended to view almost any kind of document. Like Konqueror and KPDF in KDE 3, Okular can be embedded in other applications.

Strigi will be the default search tool for KDE 4, chosen for its speed and few dependencies. In concert with other software like Soprano, an RDF storage framework, and the NEPOMUK specification, Strigi will provide the beginnings of a Semantic Desktop in KDE 4. Users can tag files with additional information through Dolphin, which Strigi can index for more accurate searches.

Many applications in the Extragear module have received numerous improvements with the new features of KDE 4 and Qt 4. But since they follow their own release schedule, they may not be available at the time of the first KDE 4 release. Popular applications like Amarok, K3b, digiKam, Gwenview and KOffice (though not part of the extragear module) are being ported.

Development

KDE 4 will feature a multimedia and hardware interaction API, called Phonon and Solid respectively. Phonon was created to address the shortcoming in the KDE 3 series of depending on a single multimedia framework. Phonon interacts with various multimedia frameworks by "engines" that allow access to a simple API that works with any framework supported by an engine. This also ensures a stable API for KDE 4’s life time. Solid is similar to Phonon as it functions as a wrapper to provide hardware interaction via a simple API. Both of these allow for easy porting of applications since KDE 4 will be available on Windows and OS X as well as Linux. Trolltech, the creators of the Qt toolkit, have adopted Phonon for their multimedia solution and have donated backends for OS X, Windows and Gstreamer to the main KDE Subversion repository under the LGPL. Trolltech has also announced all future development on backends and Phonon itself will take place within KDE SVN.

Kross is the new scripting framework for KDE 4. Kross itself is not a scripting language, but makes it easier for developers to add support for other scripting languages. Once an application adds support for Kross, any language Kross supports can be used by developers. New scripting languages can be added by creating a plugin for Kross, which benefits all applications using it.

Decibel is a Telepathy based communication framework, which is expected to be fully used by Kopete by KDE 4.2 and will allow for easy embedding of chat inside applications.

KDE 4 will be using CMake for its build system. Since previous versions of KDE were only on Unix systems, autotools were used, but a new build system was needed for builds on operating systems like Windows and Mac OS X. CMake also dramatically simplified the build process. The autotools build system had become so complicated by KDE 3 that few developers understood it, requiring hours of work for simple changes. In early 2007 CMake was shown to compile the KDE 4 version of KDElibs 40 % faster than the autotools compiled KDE 3 version.

Akonadi is a new PIM framework for KDE 4 that will be included in late releases. Akonadi is a unification of previously separate KDE PIM components. In the past each applications would have its own method for storing information and handling data. Akonadi itself functions as a server that provides data and search functions to PIM applications. It is also able to update the status of contacts. So if one application changes information about a contact, all other applications are immediately informed of the change.

Pre-releases

Alpha releases

Screenshot of KDE 4.0 Alpha 1

On May 11 2007, KDE 4.0 Alpha 1 was released marking the end of the addition of large features to the KDE base libraries and shifting the focus onto integrating the new technologies into applications and the basic desktop. Alpha 1 included new frameworks to build applications with, providing improved hardware and multimedia integration (through Solid and Phonon), new applications that focus on a smooth user experience (such as the file manager, Dolphin and Okular, the document viewer) and a new visual appearance through Oxygen icons.

On 2007-07-04, KDE 4.0 Alpha 2 was released. The release focused on integrating the Plasma desktop, improving functionality and stabilizing KDE.

Beta releases

Screenshot of Beta 1 showing the run dialogue, clock plasmoid and Dolphin file manager

Screenshot of KDE 4.0 Beta 2

Screenshot of KDE 4.0 Beta 4, showing the new Kickoff menu

On 2007-08-02, KDE 4.0 Beta 1 was released. Major features included a pixmap cache – speeding up icon loading, KDE PIM improvements, improved KWin effects and configuration, better interaction between Konqueror and Dolphin and Metalink support added to KGet for improved downloads.

On 2007-09-06, KDE 4.0 Beta 2 was released with improved BSD and Solaris support. The release included the addition of the Blitz graphic library – allowing for developers to use high performance graphical tricks like icon animation – and an overhaul of KRDC (K Remote Desktop Client) for Google’s Summer of Code. Plasma was also integrated with Amarok to provide Amarok’s central context view. In addition, several improvements made during the Summer of Code (color mixing, music notation, Flake architecture) were included in the release of the third alpha for KOffice 2.

On 2007-10-16 KDE 4 Beta 3 was released. The beta 3 release is focused on stabilizing and finishing the design of libraries for the release of the KDE Development Platform. The major improvements include improvements to Plasma with many new features and the addition of the applet browser. The KDE PIM software set will not be completely ready for the 4.0 release, but many applications have been ported with improvements. The new Akonadi PIM service is planned to be finished by the 4.1 release. The Educational software received many improvements in Marble, Parley (formerly known as KVoctrain) with bugfixes in others. A program called Step, an interactive physics simulator, was started and finished as part of the Google Summer of Code. Kopete will receive a straight port to be ready by 4.0 and there were also general Konqueror and KHTML improvements.

On 2007-10-30 KDE 4 Beta 4 was released. A list of release blockers was compiled, listing issues that need to be resolved before KDE will start with the release candidate cycle for the desktop. The goals were to focus on stabilization and fixing the release blockers. At the same time, the first release candidate of the KDE 4.0 Development Platform was released. The development platform contains all the base libraries to develop KDE applications, including “high-level widget libraries, a network abstraction layer and various libraries for multimedia integration, hardware integration and transparent access to resources on the network.”

Release candidates

Screenshot of KDE 4.0 RC2 showing Dolphin and Konqueror

On November 20 2007 KDE 4 RC1 was released. While the main site had no problems, the Plasma site went down due to the massive traffic.

On 2007-12-11 KDE 4 RC2 was released. The codebase was declared feature-complete. Some work was still required to fix bugs, finish off artwork and smoothen out the user experience.

External links

• Regularly updated Live CD from a KDE developer
• TechBase – Information site for KDE, currently mostly developer information
• Plasma – Desktop Interface project for KDE 4
• Solid – Hardware project for KDE 4
• Phonon – Multimedia project for KDE 4
• Oxygen – Icon project for KDE 4
• Decibel – Project providing a service architecture to make chat and phone communication universally available to desktop applications
• List of links to articles about KDE 4 (sorted chronologically)
• Previewing KDE 4
• KDE 4 for Mac OS X
• How to setup KDE 4 on your Mac walk-through
• Linux Action Show interview with Aaron Seigo about KDE 4, part 1
• Linux Action Show interview with Aaron Seigo about KDE 4, part 2